D.-c. to a.-c. signal converter with variable frequency output



Dec. 7,

Filed Nov. 8, 1965 W. A. GEYGER 2 Sheets-Sheet 1 Q +u DJ E E II) 2 ON H U -U HQ [K Q8 f4 0 E g 3 0 3 Lu Q INVENTOR.

Will/21m A. Geyger ATTORNEY Dec. 7, 1965 w. A. GEYGER 3,222,613

D-C TO A--G SIGNAL CONVERTER WITH VARIABLE FREQUENCY OUTPUT Filed Nov. 8, 1963 2 Sheets$heet 2 LOAD E ve

/0/ I 2 0\ Q2 r R g R l INVENTOR.

William A. Geyger BY W ATTORNEY t miw lmlnnr naltuaInathist type 1otridevicea-awtoroidal corewhavingnan 3;

auxiliary apertureuisausedxcon whichhtwotwindin'gs are placedi ilz lhis typeznofi device requires it a: LSPCClfilgCOIE construction in which1ankuadditionalzaperture in a core is needed. The two windings are wound throughthis-apertureuwSuch a relatively: small :1 aperture or :core wwindow tic;

imposes 1 stringent alimitations, upon theuwindingt arrangement, that is, very thin wire mH SLbQiHS GdMtO lget a sulficient number of turns for the magnetizationiof the core. This (also *1 means: E'that the 1 copper iresis'tance =of ;rsuch a winding is necessarily: high, increasing-the ooppernlosses Ofrthe circuitwInl-sthe present; invention lthfi'llfidL for t such an unusual core zdesigmlwith an?radditionalwaperture is eliminated by replacing thistcorelwithtwoconventional toroidal-cores.: With this arrangementnogspeciah apertures are needed thus nreducing the; manufacturing lrequiremerits, considerably; Further, thewindingsi'on these cores may have' greater number-p13turnsyasithe windingsarnay be disposed throughout :the rlIOI'Old Score; 2 y f UA I LObjeCt ofthis invention isnto;provid an improved D.-C. to A.-C. conversion system in whicl-pthe t-output voltage has a :frequency proportional: to ;the* magnitude of the applied variable directcontrol tcurrent m mAnother object o'fthis invention isxtnaprovideyan improved D.-C. to Arc converter in which ordinary toroidal cores are employed in a saturable ireaotor circuitI 1 :1 Al further object of- .this inventionis to :provide a saturable reactor "circuit for; determining theoutput lf-requency oft tavsimplified switching transistor magnetio core multivibrator :in which ordinar y toroidal1 COIBSI are I employed invsaidisaturablegreactorgcircuitw a u u a g A still further ob'ject ofl thisjinventionzis to; provide a simplified magnetic coupled multivibrator with afsaturable reactoricircuit;comprising a; p airaof ordinary toroidal Cotes.

Other objects and many of the attendant advantages oft this invention will be 1 readilyi appreciatedwas the. same becomes better understood; iby -reference to the following detailed description when considered with the accompanys aw n s iwhe e m a i o mm" n "FIG. 2 of the drawings illustrates 111 gra the relationship between a DC. control'voltag and the A.-C. output tre guen cyl of; a magnetic core multivibrator; and 4 t the; patent to i i wf l ll h, l FIG. 3 of the drawings rillustrateswa differential type magnetic rnultivibratorl m l: iReferring now to FIG. 1 ot the drawings; a Dz-Gwto A.-(,\ signal converter is shownuhaving two: zsaturabl'e'weactors in the output *cirouitofatransistor magnetic coupled multivib'rator. iSaturable reactors SR l and SR having windings N and N arer connected to the output circuitof 3 the multivibrator. .iThe multivibratori is l: comprised of two Load rwindings N and Ng ro f satlirable reactors SR1 switching 1 transistorsuQ 1 and: iQ a: The -base =of itransistor Q is connectedgto the collector terminal ofLtransistor Qg throughkresistor R Thebase' oflitransistor Q is com nected "to the i collector terminal of transistor Q through resistor R Theemitter terminals of transistors Q 'and Q -are connected together. nSaturableU reactor SRiwis provided "with saturable core l l, load windingiN land control winding: 1C :Saturable 1' reactor SR "is provided with saturable core 13, load winding N andlcontrol windingfi t 'nd SR are serially connectedttot'output.terminals 15 and 1=7 of tliemultivibrato'r. 5 Load 1L9 is'alsoconriectedito output terminals 15 and: 17: i The multivibra'tor is energized tbyt 2a Dn-C. voltage source E 55 which is-1onnected-lthri5ugh resistor R to terminals 21 :and 23. Tc-Qontroh windings G i'and C are interconnectedlin series op posing relatiom ship "to polarity reversible signali'lvoltage sourcewfigg throughvariableresistorR 5 w wwx-a w in operation, l theffrequency; .f r of the outpiit voltage E will be: determined by the saturable reactors SRfan'd SR c i in 7' i MReferring now to FIG 2- ofthe drawingsiin; whichazi graph is shown illustrating the relationshiptsbetweeh lthe input control current; I y'and\tiitoscillation frequency; f of the output voltage of 1 thernultivibrator'of FIGJ ,'-the curve "shows results: of a test of it the multivibratorio'fi this invention in which the control current (was? applied lin 0:5 milliampere steps ranging inwvalue from inilli'i anipe'resto +1.5 inilliamperesa Tape woundwoores 'wre a used having an outside diameter of1.5"i1ichesa1idan in first multivibrator includes transistors Qi' ,Q' itand a second multivib'ra tor includes transisto'rs'Q and" Q In the first multivibrator, the base of transistor Q' is' com nected to the collector terminal of transistor Q through resistor R12 Thebase of tr ansistor Qg is 'connecte'd to 1 y the collector te'rminal of transistor through resistor are connected together at a common juncture 1011 A first saturable reac'tor SR1" includes 'satiirable core' its,

rimary winding Ni'; secondary or load winding Ng 'i and '1 control winding C A second saturable reactofijSRi hrsashtr sistsa w R22 Ih em terf ermmal t c tread tors Q saturable reactor SR includes saturable co includes saturame core primar tvindingN; "secondary or lodd winding N and control winding C mary windings N and N areconnected in s 1e aiding relations p to th e cdllectorterrniiials'ii ftransistors l i t it 7 n 1 control Winding C Primary windings N and N are connected in series aiding relationship to the collector terminals of the transistors Q and Q The two multivibrators may be energized by a common voltage source E which is connected to junctures 121 and 123. The secondary windings N N N and N, are connected in series aiding relationship to load 125. Control windings C and C are connected together in series opposing relationship. Control windings C and C are also connected together in series opposing relationship. The control circuit of the first multivibrator, including windings C and C is serially connected to the control circuit of the second multivibrator, including windings C and C and to signal voltage source E through resistor R In such a combined control circuit, the winding sense relationship of the windings may be considered in terms of magnetic flux directions. That is, for example, if a current flow I flowing through winding C created a mag netic flux in core 103 in a clockwise direction, this same current flowing through windings C and C would produce a counter-clockwise magnetic flux in cores 105 and 113, and the flow of this same current through winding C would produce a magnetic flux in a counter-clockwise direction in core 115.

With the differential or push-pull type of circuit arrangement of FIG. 3, the frequency of the first multivibrator comprising transistors Q and Q will be the same as the second multivibrator when there is no DC. signal applied to the control circuit, that is when E =0. When a signal is applied to the control circuit, the frequency of the first multivibrator f will decrease and the frequency of the second multivibrator f will increase, for example. The frequency of the output voltage will then be the difference frequency, that is, f ==f "-f As the signal is decreased or becomes negative the opposite is true, that is, the frequency of the first multivibrator will increase and the frequency of the second multivibrator will decrease.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that Within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A differential D.-C. to A.-C. converter having an A.-C. voltage output with a frequency proportional to the magnitude of a D.-C. signal voltage comprising,

a first switching transistor multivibrator having output circuit,

a second switching transistor multivibrator having an output circuit,

a first saturable reactor having a first primary winding,

a first load winding and a first control winding,

a second saturable reactor having a second primary winding, a second load winding and a second control winding,

a third saturable reactor having a third primary winding, a third load winding and a third control winda fourth saturable reactor having a fourth primary winding, a fourth load winding and a fourth control winding,

means connecting said first and second primary windings to the output circuit of said first multivibrator in series aiding relationship,

means connecting the third and fourth primary windings to the output circuit of said second multivibrator in series aiding relationship,

means connecting said first and second load windings in series aiding relationship to form a first load circuit,

means connecting said third and fourth load windings in series aiding relationship to form a second load circuit,

means connecting said first and second control windings in series opposing relationship to form a first control circuit,

means connecting said third and fourth control windings in series opposing relationship to form a second control circuit,

a load,

a D.-C. signal voltage source,

means connecting said first and second load circuits to said load in series aiding relationship,

means connecting said first and second control circuits to said D.-C. signal voltage source in series opposing relationship.

2. A differential type DC. to A.-C. converter having an A.-C. output voltage with a frequency proportional to the magnitude of a D.-C. signal voltage comprising,

a first magnetic coupled multivibrator having an input circuit and an output circuit,

a second magnetic coupled multivibrator having an input circuit and an output circuit,

first saturable reactor means including saturable core means, a control circuit, a first load circuit and a second load circuit,

second saturable reactor means including saturable core means, a control circuit, a first load circuit and a second load circuit,

a D.-C. voltage source,

means connecting the input circuit of said first multivibrator to said D.-C. voltage source,

means connecting the input circuit of said second multivibrator to said D.-C. voltage source,

means connecting the first load circuit of the first saturable reactor means to the output circuit of said first multivibrator,

means connecting the first load circuit of said second saturable reactor means to the output circuit of said second multivibrator,

load means,

means connecting the second load circuit of said first saturable reactor means and the second load circuit of said second saturable reactor means to said load means in series aiding relationship,

a D.-C. signal voltage source,

means connecting the control circuit of said first saturable reactor means and the control circuit of said second saturable reactor means to said D.-C. signal voltage source in series opposing relationship.

3. A differential type D.-C. to A.-C. converter having a frequency proportional to the magnitude of a D.-C. signal voltage comprising a first switching transistor multivibrator having an input circuit and an output circuit,

a second switching transistor multivibrator having an input circuit and an output circuit,

a D.-C. voltage source means connecting said D.-C. voltage source to the input circuits of said first and second multivibrators,

a first saturable reactor system having a first primary circuit, a first control circuit and a first load circuit,

a second saturable reactor system having a second primary circuit, a second load circuit and a second control circuit,

means connecting said first primary circuit to the output of said multivibrator,

means connecting said second primary circuit to the output of said second multivibrator, load means, a polarity reversible D.-C. control signal source, means connecting said first and second load circuits to said load means in series aiding relationship,

means connecting said first and second control circuits to said D.C. control signal source in series opposing relationship.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Evans et a1 331-413 Van Allen 331--113 Clark 311-113 Rochelle =33 1--1 13 Samusenko 331-113 Rochelle 33 1-1-13 Bayne 331--113 Paull 331113 Lloyd 331 413 ROY LAKE, Primary Examiner.

JOHN KOMINSKI, Examiner. 

3. A DIFFERENTIAL TYPE D.-C. TO A.-C. CONVERTER HAVING A FREQUENCY PROPORTIONAL TO THE MAGNITUDE OF A D.-C. SIGNAL VOLTAGE COMPRISING A FIRST SWITCHING TRANSISTOR MULTIVIBRATOR HAVING AN INPUT CIRCUIT AND AN OUTPUT CIRCUIT, A SECOND SWITCHING TRANSISTOR MULTIVIBRATOR HAVING AN INPUT CIRCUIT AND AN OUTPUT CIRCUIT, A D.-C. VOLTAGE SOURCE MEANS CONNECTING SAID D.-C. VOLTAGE SOURCE TO THE INPUT CIRCUITS OF SAID FIRST AND SECOND MULTIVIBRATORS, A FIRST SATURABLE REACTOR SYSTEM HAVING A FIRST PRIMARY CIRCUIT, A FIRST CONTROL CIRCUIT AND A FIRST LOAD CIRCUIT, A SECOND SATURABLE REACTOR SYSTEM HAVING A SECOND PRIMARY CIRCUIT, A SECOND LOAD CIRCUIT AND A SECOND CONTROL CIRCUIT, 